This invention relates to coating compositions useful as floor finishes. The floor finishes use a polymer having a unique particle size and a unique particle size distribution and a higher than normal solids content by weight.
The floor finish industry has used aqueous floor cleaning, coating and polishing compositions containing acrylic type polymers, a fugitive plasticizer, tributoxyethyl phosphate, surfactants, antifoaming agents, bicarbonate, water, ammonia and other copolymers for some time. Generally the polymers and copolymers employed in these compositions have solids contents of 38-40 percent by weight. The compositions have a solids content of from 15-25 percent by weight. Because of the low solids content, one can apply the finishes with a conventional string mop. Higher solids content finishes are too viscous for standard mopping. Finishes with solids contents of 15-25 percent generally requires 3-6 applications to build up satisfactory film thickness to offer adequate shine and protection.
The coating compositions of this invention includes a polymer having a controlled particle size, a controlled particle size distribution, and a higher than normal solids content by weight. The preferred polymer is an acrylic polymer and more specifically is a copolymer of styrene, acrylates and acrylic acid. The preferred composition has a solids content of 30-40 weight percent and a viscosity of less than 10 centipoise (cps). More preferably, the composition has a solids content ranging from 30-37 weight percent. These unique properties allows the floor finish to be applied with a conventional string mop. Once the viscosity of a floor finish is above 10 centipoise, the finishes become difficult to apply with a conventional mop. Because of the higher percent by weight solids content, only 2-4 applications are required to build up adequate shine and protection rather than 3-6 required by conventional floor finishes containing 15-25 weight percent by solids. The solids content is determined by testing according to ASTM Specification D-2834.
The polymer we use in our floor finish may vary widely. The polymer may be any polymer suitable for use in a floor finish. The key is that the polymer have the following controlled particle size, controlled particle size distribution and a higher than normal solids content.
Generally, the polymer has an average particle size ranging from 150-300 nanometers (nm). Preferably, the range is 150-250 nm. Generally, the particle size distribution is a Gaussian distribution with xcx9c80% of the particles falling within +/xe2x88x9230 nanometers of the average particle size.
Generally, the solids content of the polymer is 40-60 weight percent. Preferably, the solid content of the polymer ranges from 50-60 weight percent.
Preferably, the polymer is an acrylic polymer. These include polymers, copolymers or terpolymers of acrylic acid or methacrylic acid with esters of acrylic or methacrylic acid, hydroxyethyl methacrylate methacrylonitrile, acrylonitrile or the like. Other monomers may be employed in this invention, including methyl methacrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate.
Other unsaturated acid monomers can also be substituted in part for the preferred methacrylic acid. Such unsaturated acid monomers include maleic acid, crotonic acid, fumaric acid and itaconic acid.
The vinyl component preferably is styrene or a monoalkenyl aromatic monomer such as methyl styrene or tertiary butyl styrene. It is possible to substitute for a portion of the water insoluble vinylic monomer, a relatively soluble vinylic monomer, such as vinyl acetate and methyl acrylate.
Typical preferred copolymers include; styrene/butyl acrylate/methacrylic acid, styrene/ethyl acrylate/methacrylic acid, and styrene/butyl acrylate/ethyl acrylate, methacrylic acid. Other polymers include; styrene/butyl acrylate/acrylic acid, styrene/ethyl acrylate/acrylic acid, and a styrene/butyl acrylate/ethyl acrylate/acrylic acid, and methyl styrene/styrene/butyl acrylate/ethyl acrylate/methacrylic acid/acrylic acid.
The floor finish may contain one or more polyalkene waxes such as an oxidized, low-density ethylene homopolymer; an oxidized, low-density ethylene/acrylic acid copolymer; or a chemically modified polypropylene at up to 10 weight percent.
The floor finish may contain one or more non-fugitive plasticizers such as tributoxyethyl phosphate, 2,2,4-trimethyl-1,3 pentanediol diisobutyrate, dibutyl phthalate, dioctyl phthalate, and caprolactam. Generally, tributoxyethyl phosphate and dibutyl phthalate are the preferred non-fugitive plasticizers at up to 10 weight percent.
The floor finish may contain one or more fugitive plasticizers/coalescents such as ethylene glycol, diethylene glycol methyl ether, diethylene glycol ethyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, diethylene glycol monobutyl ether acetate, glycol 2-ethylhexyl ether, and 2,2,4-trimethyl-1,3-pentanediol mono (2-methyl propanoate). Generally diethylene glycol ethyl ether and dipropylene glycol methyl ether are the preferred fugitive plasticizer/coalescents at up to 10 weight percent.
The floor finish may include optional ingredients defined herein below. The finish may optionally include up to 0.05 weight percent of an antifoaming agent.
The finish may also include up to 0.3 weight percent formaldehyde or benzoisothiazoline to ensure xe2x80x9cquick killxe2x80x9d of any organisms with which the instant composition may be contaminated, particularly during manufacture and packaging. The formaldehyde, if employed, can be conveniently added as a 37% solution in water (formalin).
The finish optionally may include, as a film modifying agent, either an alkali-soluble rosin ester resin or an alkali-soluble low molecular weight copolymer of styrene and maleic anhydride in order to enhance leveling and the hardness of the deposited film. The rosin ester resin or the styrene/maleic anhydride copolymer can be employed in a concentration up to about 5 weight percent of the instant composition.
The floor finish may be applied to flooring using well known techniques, e.g. by mopping with a string mop or other floor finish applicator. The composition should be applied to flooring as an even thin layer and allowed to dry thoroughly.
The floor finish essentially is a translucent to opaque liquid having good storage stability. The film deposited there from is clear and resistant to discoloration, has high gloss, and exhibits excellent wearability, scuff resistance and water spotting resistance. The floor finish passes the ASTM D 2047 test for slip resistance.
The composition or floor finish may be applied to a variety of floor substrates including but not limited to vinyl tile, vinyl composition tile, vinyl asbestos tile, concrete, terrazzo, marble, quarry tile, ceramic tile, and wood.
The following examples illustrate this finish without being limited thereto.